1 files changed, 81 insertions, 0 deletions
diff --git a/test/files/run/t3346e.scala b/test/files/run/t3346e.scala
new file mode 100644
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+++ b/test/files/run/t3346e.scala
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+import scala.language.implicitConversions
+import scala.collection.generic.CanBuildFrom
+import scala.math.Ordering
+import collection.{TraversableLike, SeqLike}
+import collection.immutable.BitSet
+
+class QuickSort[Coll](a: Coll) {
+  //should be able to sort only something with defined order (someting like a Seq)
+  def quickSort[T](implicit ev0: Coll => SeqLike[T, Coll],
+                   cbf: CanBuildFrom[Coll, T, Coll],
+                   n: Ordering[T]): Coll = {
+    quickSortAnything(ev0, cbf, n)
+  }
+
+  //we can even sort a Set, if we really want to
+  def quickSortAnything[T](implicit ev0: Coll => TraversableLike[T, Coll],
+                           cbf: CanBuildFrom[Coll, T, Coll],
+                           n: Ordering[T]): Coll = {
+    import n._
+    if (a.size < 2) {
+      a
+    } else {
+      // We pick the first value for the pivot.
+      val pivot = a.head
+      val (lower, tmp) = a.partition(_ < pivot)
+      val (upper, same) = tmp.partition(_ > pivot)
+      val b = cbf()
+      b.sizeHint(a.size)
+      b ++= new QuickSort(lower).quickSortAnything
+      b ++= same
+      b ++= new QuickSort(upper).quickSortAnything
+      b.result
+    }
+  }
+}
+
+class FilterMap[Repr](a: Repr) {
+  def filterMap[A, B, That](f: A => Option[B])(implicit ev0: Repr => TraversableLike[A, Repr],
+                                               cbf: CanBuildFrom[Repr, B, That]): That = {
+    a.flatMap(e => f(e).toSeq)
+  }
+}
+
+class FilterMapFixed[A, Repr <% TraversableLike[A, Repr]](a: Repr) {
+  def filterMap2[B, That](f: A => Option[B])(implicit cbf: CanBuildFrom[Repr, B, That]): That = {
+    a.flatMap(e => f(e).toSeq)
+  }
+}
+
+object MyEnhancements {
+  implicit def toQS[Coll](a: Coll) = new QuickSort(a)
+  implicit def toFM[Coll](a: Coll) = new FilterMap(a)
+  implicit def toFM2[A, Repr <% TraversableLike[A, Repr]](a: Repr) = new FilterMapFixed(a)
+}
+
+object Test extends App {
+
+  import MyEnhancements._
+
+  println("qwe".quickSort)
+  println(Array(2, 0).quickSort.toList)
+  println(Seq(2, 0).quickSort)
+  //not very useful to sort a set, but just as a demonstration
+  println(BitSet(2, 0).quickSortAnything)
+
+  //need to hint type inferencer,
+  //probably will be able to overcome after https://issues.scala-lang.org/browse/SI-4699  and
+  // related issues are  fixed (by moving ev0 parameter from filterMap to toFM), see toFM2
+  println("qwe".filterMap((c: Char) => Some(c.toInt)))
+  println("qwe".filterMap((c: Char) => Some(c)))
+  println(Array(2, 0).filterMap((c: Int) => Some(c.toInt)).toList)
+  println(Seq(2, 0).filterMap((c: Int) => if (c < 2) Some(c + "!") else None))
+  def test(i:Int) = Option(i)
+  println(BitSet(2,0).filterMap(test))
+
+  println(toFM2("qwe").filterMap2(c => Some(c)))
+  println(toFM2(Array(2, 0)).filterMap2(c => Some(c.toInt)).toList)
+  //No implicit view available from java.lang.String => scala.collection.TraversableLike[A,java.lang.String]. :(
+  //Not anymore :)
+  println("qwe".filterMap2(c => Some(c)))
+}